Reducing energy loss

• What are the two main methods discussed to reduce unwanted energy transfers?

  Thermal insulation and lubrication
• Why is it important to understand the principles of energy transfer reduction in the exam?

  • Allows you to apply principles to specific exam questions
  • Enables you to suggest solutions to reduce energy loss in different scenarios
• What are the main methods to reduce heat loss in a home?

  • Sealing closed to prevent air passing out
  • Using thick walls with low thermal conductivity materials
  • Incorporating cavity walls
  • Adding insulating foam to cavity walls
  • Using double glazing windows
• Why do most people prefer their homes to be warm even in freezing cold outside temperatures?

  To maintain a comfortable living environment and body temperature
• What does thermal conductivity refer to in the context of thermal insulation?

  The ability of a material to conduct heat
• How does sealing a house help reduce heat loss?

  By preventing heat loss through air convection
• What is conduction?

  When heat is lost directly through a solid
• What method of heat transfer is reduced by having foam seals around doors and windows?

  Convection
• What type of materials are used for thick walls to reduce conduction?

  Materials with low thermal conductivity
• What are cavity walls and how do they help reduce conduction?

  • Two layers of bricks with a small air gap between
  • Air gap reduces conduction because air is a poor conductor
• What is the purpose of filling cavity walls with insulating foam?

  To reduce convection by introducing air bubbles that hinder air movement
• What is the difference between single glazing and double glazing?

  Single glazing has one pane of glass while double glazing has two panes with an air gap between them
• How does double glazing reduce heat loss compared to single glazing?

  • Double glazing has two layers of glass separated by an air gap
  • Air gap acts as an insulator reducing conduction
  • Prevents heat from being conducted from inside to outside
• What is friction?

  The resistance that an object encounters when moving over a solid or through a fluid
• How does friction affect energy transfer efficiency?

  It reduces efficiency and can cause objects to heat up
• Why does friction between the cogs and chain of a bicycle make pedaling harder?

  Because it creates resistance that needs to be overcome
• What is a lubricant?


  A substance used to reduce friction between surfaces
• How does streamlining affect energy transfer efficiency in cars and planes?

  • Reduces air resistance by smoothing the shape
  • Allows for less fuel consumption
  • Increases energy transfer efficiency